Yes. A flash can be mounted on a tripod with a shoe-to-tripod adapter or, in many cases, with the small flash stand that comes with the speedlight.

Common options:

• cold shoe adapter: physically holds the flash and screws onto the tripod. Best if the flash will be triggered optically or by a radio trigger attached elsewhere.
• hot shoe adapter: mounts on the tripod and also provides an electrical connection for triggering, such as via a PC sync cable on some models.
• included flash stand: many speedlights include a small plastic foot/stand with a threaded socket, which can often be attached directly to a tripod plate.

There are also simple locking cold shoes made of plastic that are compact and won't scratch or stress the flash foot.

So the main question is not whether it can be mounted—it can—but how you want to trigger it. If you only need a holder, a cold shoe or the supplied stand is enough. If you need a wired connection through the mount, look for a hot shoe adapter with the appropriate sync option.